Copy Left Audio to Right for "Stereo"

Need your help. I have a project I'm working on right now. Audio was recorded with lav mics into a Zoom h1 recorder. Not sure if setting or the lav mic is the issue, but it only recorded on one side of the channel, e.g. left. It's not that noticeable when using straight up computer speakers, but very noticeable when using headphones. Is there a way to mirror the left channel to the right in hitfilm? Or do I have to use an outside program if possible? What program may that be?

Happened to me as well. I was using a lapel mic too, but maybe it wasn't correctly plugged in... One track had nice sound, the other one was barely earable (is "earable" an English word?). Anyhow...

DON'T convert stereo to mono, as this will average both tracks into one, meaning you'll end up with a single track with half the audio level of the good one!

Instead, separate the tracks to stereo (drop-down menu in the box at the beginning of the track), select the track with the good sound, copy and paste onto the other track. Check if one track is set to "left track" and the other one to "right track" (should already be that way), and "join to stereo". Done.

I'm not sure I gave you the exact words for the menu, as my menus are in French, but I hope you get the idea

In my "other editing program" I use a pan channels feature to duplicate, say the left channel, to the right so that both tracks are identical. But as @Cervier has pointed out, I have to boost the level to get that back up to the original (which really was never a problem as long as the audio is clean).

Cut and paste is a good way to go, though.

I still recommend having Audacity in your toolkit. Just handy to have.

I'm having the same issue as well with HitFilm 2017 Pro. I have 400+ shots with audio only on the left channel. Using Audacity to add audio to the right channel and then syncing them in HitFilm would be a nightmare. In the past I used Premiere's "duplicate left" effect to easily fix this issue. I don't want to go back to Adobe, but at this point I have no choice.

Having the same problem, and this just needs to be there. When doing interviews with one channel for shotgun mic and another for a lavalier, i need to be able to choose which channel i want to use.This REALLY needs to be added ASAP